Cam shaft drive for radial engines



Oct. 9, 1934. G. w. CODRINGTON 1,975,826

' CAM SHAFT DRIVE FOR RADIAL ENGINES Filed Jan. 21. 1931 Gaye M Kaahr'y 52/! W W w Patented Oct. 9, 1934 1,975,826 .CAM SHAFT DRIVE FOR RADIAL ENGTNES George -W. Codrington, Lakewood, Ohio Application January 21, 1931, Serial No. 510,303 3 Claims. (01.123-90) This invention relates to cam shaft drives for multiple cylinder internal combustion engines. More particularly the invention is applicable to such an engine having a plurality of angularly related cylinders disposed about a crank of the engine crank shaft to form the principal parts of what is known as a radial engine since the cylinders extend radially of the shaft.

These cylinders, in a plane, may be considered 319 as a set; and this invention is particularly adapted to an engine whose crank shaft has a plurality of cranks and such a set of angularly related cylinders, radially disposed about each crank. By this arrangement there are a numher of rows of cylinders each extending along the crank shaft, each row lying in a plane where the number of cylinders is the same for each set and the sets are in registry. Obviously by this arrangement an engine of great power may be built although each cylinder unit thereof be relatively small. The arrangemen therefore, has many advantages, yet a difiiculty has been in providing for actuation of the large number of valves therein.

This invention contemplates the provision of a single cam shaft for each row of cylinders, so that there will be as many cam shafts as there are cylinders in a set, and the invention provides novel means for driving all of these 30. cam shafts from the crank shaft, the means being simple and reliable and located at an end of the engine.

The exact nature of the invention together with further objects and advantages thereof will be apparent from the following description taken in connection with the accompanying drawing, in which Fig. 1 is a longitudinal section of an end portion of an engine showing an embodiment of my invention applied thereto and Fig. 2 is an end elevation of the same, the section of Fig. 1 being as indicated by line 1--1, Fig. 2.

With reference now to the drawing, the engine comprises a crank case 1 in which a crank shaft 2 is mounted. About the crank case for each crank thereof is a set of angularly related cylinders 4, nine being shown for each set. Thus for each cylinder of the first set there may be a row of cylinders extending along the crank case in the plane of the crank shaft 2.

The details of the cylinders and their immediately associated parts are immaterial, it being sufficient to say that each cylinder has a piston associated with its crank by a connecting rod -in a manner which will be well understood by one familiar with the art. Each cylinder also has a pair of valves, one for inlet and one for exhaust, which valves are of poppet type and adapted to be actuated from cams on a cam shaft through suitable interposed means such as pushrods and rockers. Such arrangement also will be recognized by one familiar with the art.

According to this invention I provide for each row of cylinders, a cam shaft 10, each cam shaft being suitably mounted in the crank case, extending along between the base portions of adjacent rows of cylinders. Each cam shaft 10 carries suitable cams for cooperating with the described valve gear to operate the valves of the cylinders of its row. There are thus in the engine shown, nine cam shafts disposed about the crank shaft 2 in parallel relation therewith and equidistant therefrom.

According to my invention 1 provide at the end of each cam shaft a crank 12, the cranks 12 being all of equal throw and all extending in the same direction when the cams ll of all of them are in properly timed relation. The crank pins 13 of all of the cranks 12 are joined by a plate 14 which may carry for each crank an inset 15 to provide suitable bearing. 'It will be apparent that to actuate all of the cam shafts 10 to control all of the valves 7 it is only necessary that the plate 14 be given oscillatory motion about the crank shaft 2 at a speed half of that of the latter and in a circular path corresponding to the throw of the cranks 12.

A gear secured 1901. upon the end of the crank shaft 2 meshes with a pinion 18a secured upon a fixed stub shaft 16a. This pinion 18a meshes with an internal gear 39 mounted on the stepped down extremity 31 of the crank shaft 2. This internal gear 30 has an eccentric portion 32 upon which the plate 14 bears to receive motion therefrom, the eccentricity of the portion 32 being equal to and unidirectional with that of the cranks 12. With this construction the gearing, which will be recognized as of planetary type, causes the eccentric 32 to move in the opposite direction from the shaft 2 and at half speed of the latter; so that its motion is transmitted by the plate 14 to all of the cam shafts 10.

What I claim is:

1. In an internal combustion engine having a crank shaft, a plurality of cylinders arranged thereabout and a cam shaft for each cylinder, said cam shafts being parallel, a plate, and cranks of equal throw joining each cam shaft with said plate to define an oscillatory path for the latter, means associating said plate with said crank shaft to impart said motion to said plate to:

cause rotation of said cranks, said means comprising a driving gear fixed on said crank shaft, a larger driven gear mounted coaxially With said driving gear, idler gearing between said driving and crank means interasso- 2. In' an internal combustion engine having a crank shaft, a plurality of cylinders arranged thereabout and a cam shaft for each cylinder,

'said cam shafts being parallel, a plate, and 'cranks of equal throw joining each cam shaft with said plate to define an oscillatory path for the latter, means associating said plate with said crank shaft to impart said motion to said plate to cause rotation of said cranks, said means comprising a driving gear fixed on said crank shaft, a larger drivenflgear rotatably mounted on said crank shaft, idler gearing between said driving and driven gears, and crank means interassociating said driven gear and said plate.

3. In an internal combustion engine having a crankshaft, a plurality of cylinders arranged thereabout and a cam shaft for each cylinder, said cam shafts being parallel, a plate, and cranks of equal throw joining each cam shaft with said plate to define an oscillatory path for the latter, means associating said plate with said crank shaft to impart said motion to said plate to cause rotation of said cranks, said means comprising a driving gear fixed on said crank shaft, a larger driven gear arranged about said driving gear and rotatably mounted on the crank shaft, an idler pinion arranged to transmit drive from said drivingl'gear tosaid driven gear, and crank means interassociating said driven gear and said plate.

' GEORGE W. CODRINGTON. 

